Solderless connector terminal structure



July 1957 c. JONES 2,799,012

SOLDERLESS CONNECTOR TERMINAL STRUCTURE Filed April 5, 1954 I INVENTORATTORNEY m 7 Charles L.Jones,.

United SOLDERLESS CONNECTOR TERMINAL STRUCTURE Application April 5,1954, Serial No. 420,919

9 Claims. (Cl. 339-265) My invention relates, generally, to terminalconstructions for electrical equipment such as circuit interrupters and,more particularly, to connectors of the solderless type.

An object of my invention is to provide a connector which shall besuitable for connecting either one or a plurality of cables to aterminal.

Another object of my invention is to provide a connector capable ofreceiving cables of different sizes.

A further object of my invention is to provide a connector which may beinstalled in a relatively narrow space and requires much less space inthe direction along the length of the circuit interrupter.

Still another object of my invention is to provide a connector havinginterlocking parts for preventing the strands of a stranded cable frombeing squeezed out of proper position and interfering with thetightening of the connector.

A still further object of my invention is to provide a connector havingcertain identical interchangeable parts to keep the tool and inventoryexpense low.

An additional object is to provide a terminal construction for a circuitbreaker or other electrical device in which no live parts are exposedadjacent the end of the insulating housing of the circuit breaker.

Other objects of my invention will be explained fully hereinafter orwill be apparent to those skilled in the art.

ate

My invention provides several improvements over the two types ofterminal constructions illustrated, for example, in Grissinger et al.Patent No. 2,435,305, issued February 3, 1948. One improvement residesin thefact that my novel terminal takes up much less space in thedirection of the length of the circuit breaker and does not extend to apoint close to the end of the insulating housing so that the live partsare protected from being accidentally touched either by a person whowould be shocked or by a tool which could cause a short circuit. Myconnector is of the solderless type and has the further advantages thatit is adjustable to receive a range of different size cables, and inaddition can receive a plurality of cables rather than just one.

These improvements are obtained by providing two threaded inserts in theinsulating base of the circuit interrupter. These are spaced apart asfar as permitted by the relative narrow width between the insulatingwalls defining the pole space, so that the end of the cable may extendinto the space between two studs threaded into the inserts and beclamped between grooved plates extending across the space between thestuds. With this construction, no live parts extend out to the end ofthe insulating housing as have the solder lugs or solderless lugs usedin the past.

In accordance with one embodiment of my invention, a connector comprisesa plurality of clamping plates which are held together by two spacedstud bolts threaded into a terminal on a circuit breaker. Each plate isrecessed around the hole for one bolt and has a projec tion around thehole for the other bolt, The recess and 2,799,012 Patented July 9, 1957the projection are so shaped that when a plate is re versed theprojection on one end fits into the recess in an adjacent plate, therebyinterlocking the two plates. The plates are preferably identical,thereby making them interchangeable. Each plate has a transverse groovetherein for receiving a cable which is clamped between two plates.

For a better understanding of the nature and objects of the invention,reference may be had to the following detailed description, taken inconjunction with the accompanying drawing, in which:

Figure 1 is a view, partly in section and partly in elevation, showing aconnector embodying the principal features of my invention utilized forconnecting cables to the terminal of a circuit breaker, only a portionof which is shown;

Fig. 2 is another view, partly in section and partly in elevation of thestructure shown in Fig. 1;

Fig. 3 is a view, in section, taken along the lines III-III in Fig. 2,the connector plates being clamped closer together;

Fig. 4 is an enlarged view, in end elevation, of one of the connectorplates;

Fig. 5 is an enlarged view, in plan, of the connector plate;

Fig. 6 is a view, in section, taken along the line VI-Vl in Fig. 5;

Fig. 7 is a view, in side elevation, of one of the stud bolts forclamping the plates together, and

Fig. 8 is a view, in end elevation, of the bolt.

Referring to the drawing, and particularly to Figs. 1 and 2, thestructure shown therein comprises an end portion of a circuit breakercasing having a base member 10 and a removable cover member 11. Thesecasing members may be composed of a suitable molded insulating material.Metal inserts 12 are molded or otherwise secured in the base member 10.As shown in Fig. 1, each insert 12 has a threaded hole therein forreceiving the threaded end of a stud bolt 13. The holes in the insertsextend all of the way through the inserts so that connection to aterminal conductor 14 may also be made from the rear of the base of thecircuit interrupter. The terminal conductor 14 has one end resting onthe inserts 12. The other end of the terminal conductor 14 may beconnected to a contact member of the circuit breaker (not shown).

In order to connect one or more cables to the terminal conductor 14, aconnector comprising a plurality of clamping plates 15 is provided. Asshown most clearly in Fig. 5, each plate 15 has two spaced holes 16 and17 extending through the plate. A recessed area 18 surrounds one of theholes 16. A raised area or projection 19 surrounds the other hole 17.

As shown in Fig. 4, the walls of the recessed area 18 have slopingsurfaces 21 and the raised area 19 has surfaces 22 which slopeoppositely from the surfaces 21. Thus, when two plates 15 are assembledin reversed rela tion the. raised portion or projection 19 of one platefits into the recessed area 18 of the other plate. In this manner thetwo plates are interlocked together when they are assembled in reversedrelation.

As also shown in Figs. 5 and 6, each plate 15 has a transverse groove 23disposed between the holes 16 and 17. The groove 23 is generallysemi-cylindrical. Thus, when two plates are assembled in reverserelation a generally cylindrical opening is provided between the platesfor receiving a cable 24.

As shown in Fig. 3, when a small or medium size cable is utilized theedges of the grooves 23 overlap each other at 25, thereby preventing thestrands of the cable 24 from being forced outside of the opening formedby the'grooves 23 when pressure is applied on the cable by tighteningnuts a 26 on the bolts 13. As shown in Fig. 1, when relatively largecables 24 are utilized the plates do not quite overlap each other butthe interlocked recesses and projections help to keep the strandsproperlybunched together when stranded cable is used. Thus, theconnector functions satisfactorily with a relatively wide range ofcable-sizes having difierent current carrying capacities.

As shown in Figs. 1 and 2, four plates 15, which are identical inconstruction, may be assembled in the manner shown to connect two cables24 to the terminal conductor 14. If it is desired to increase the numberof cables, additional plates may be assembledin the manner shown byproviding longer stud bolts 13 and ;increasing the size of the breakercasing.

As shown-in Fig.6, theside of the plate15 iopposite the recessed area 18-;a nd'the raised area 19 has -,a flat surface 27. Thefiat surfaces 27of two plates engage when the two platesaredisposed back-to-backasshownin Fig. 1. If desired, these two plates may be made as one-piecehaving-the recessed and raised portions on OPPOSi L of the plate.

Referring to Fig. -5, it wil1 be seenthat the;hole 16 has a flat side 28adjacent to the groove 23. Likewise, the hole 17 has a flat side 29adjacent tozthe groove 23- Referring to Figs. 7 and 8, it will be'seenthatithe bolt 13 has a flat side 31 similar to the flat sidesjnthe holes16 and 17. The fiat sides in the holes ;16,and 17.permit the bolts to belocated relatively close to the sides of the groove 23 withoutinterfering with ,the insertion of the cables in the openings in theconnector.

In:this manner bolts of sufficient size to have the desired strength maybeutilized without increasing thelength of the plates 15 and withoutdecreasing the strength of the plates by providing holes of sufiicientsize to take relatively large bolts. As showninFig. 8, a slot 32isprovided in one end of each bolt 13 to permit a screwdriver to beutilizedto thread a bolt into an insert 12.

Referring to .Figs. 1 and 2, it will be seen that an assembled group ofplates 15, of the type herein described, may be utilized to connectelectrically two or more conductors by clamping the plates together inthe manner shown by means of bolts inserted through the holes 16 and 17todraw the plates together against the conductors. Thus, the connectorsmay beutilized as a means of splicing two or more conductors together.

One advantage of the connector is illustrated in Fig. 2 from which it isseen that the connector requires only a relative shortspace in thedirection along the length of the cable. This permits the connector tobe spaced back from the end of the enclosing housing to insure thatnolive conducting parts are accessible from the outside ofthe housing. Asshwn,-the insulation need be stripped from only-the ends of the cablesthat are to be positioned'between the plates, and the insulated portionof the cables may extend into thehousing so that no live parts areexposed to give one an electrical shock. 'This advantage is possiblewithout greatly elongating the housing because the connector utilizesthe full width available and clamps the conductors in the space betweenthe two bolts.

From the foregoing description it is apparent that I have provided aconnector which utilizes a plurality of plates which are so shaped thatthey are interlockedtogether when assembled in reversed relation,thereby retaining the plates in the assembled relation. The connector issuitable for connecting one or more cables to a terminal member. Thenumber of cables may be increased or decreased by varying the number ofplates utilized. Furthermore, cable of different sizes may be utilizedwith the connector. The connector may also be utilized for electricallyconnecting two or more cables together.

Since numerous changes may be made in the abovedescribed construction,and different embodiments of the invention may be made without departingfrom the spirit and scope thereof,it is'intended'that all mattercontained in the foregoing description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

I claim as my invention:

1. A connector for electrically connecting two or more conductorscomprising, a plurality of plates having two spaced holes therethrough,each plate having a recessed area around one hole and a raisedareaa-round the other hole, said areas having side walls which slope inopposite directions, said areas being on the same side Qfsaid plate, theopposite side of said plate being substantially fiat, said raised areaon one plate fitting into the recessedarea in another plate with saidwalls engaging each other when said plates are assembled in reversedrelation, the fiat sides of at least two of saidplates engaging .whenthe plates are assembled, each plate having a transverse groove thereinbetween said holes, said grooves forming openings between said platesfor the .conductors when the plates are-assembled-in reversed relation,and boltsdisposed in said holes for clamping the plates againsttheconductors.

2. A connector for connecting a conductor to a terminal, said connectorcomprising a plurality of plates having two spaced holes therethrough,each plate having a recessed area adjacent one hole and a raised areaadjacent theother hole, said.raised area on one plate fitting into therecessed area in another plate when said plates are assembled, eachplate having atransverse groovetherein between said holes, said groovesforming an opening between said plates for the conductor, a terminalmember, bolts extending throughsaid holes and theterminal memher. toclamp said plates against the conductor, each hole having .a flat sideadjacent to the groove in each plate, and each bolthaving a flat sidecorresponding to the flat side ina hole.

3. A connector for electrically connecting twoconductors comprising, apluralityof plates having twospaced holes therethrough, each platehaving a recessed area around one hole and a raisedarea around the otherhole, said raised areaon one plate fitting into the recessed area inanother plate when said plates are assembled, each plate having atransverse groove therein between said holes, said groovesformingopenings between said plates for the conductors when the platesare assembled in reversed relation,-bolts disposed in said holes forclamping the plates against'the conductor, each hole having a flat sideadjacent to the groove in each plate, and each bolt having a flat sidesimilar to-the flat side in a hole.

.4. A connector for connecting a conductor to a terminal, said connectorcomprising a plurality of plates having two spaced holes therethrough,each plate having -a-recessed area around one hole'and a raised areaaround the other hole, said raised area on one plate fitting into therecessed area in=another plate when said plates are assembled, eachplate having a transverse groove therein between said holes, the-edgesof said grooves overlapping to form an opening having closed sidesbetween said plates for the conductor, a terminal member, boltsextending through said holes and the terminal member to clamp-saidplates against the conductor, each hole having a flatside adjacent tothe groove in each plate, and-each bolt having a flat side correspondingto the flat side in a hole.

5. A connector for electrically connecting two conductors comprising, atleast three plates each having two spaced holes therethrough, one sideof each of two outer plates having a recessed area around one hole and araised area around the other hole, opposite sides of an intermediateplate having a recessed area around one hole and a raised area aroundthe other hole, saidraised area onone plate fitting into'the recessedarea in another plate when said plates are assembled, each outer platehaving a transverse groove therein on one side between said holes, theintermediate plate having a transverse groove therein on opposite sidesbetween said holes, the edges of -the grooves in adjacent platesoverlapping -to form an opening having closed sides between said platesfor a conductor, bolts disposed in said holes for clamping the platesagainst the conductors, each hole having a flat side adjacent to thegroove in each plate, and each bolt having a fiat side corresponding tothe flat side in a hole.

6. An electrical device having a base and cover of insulating material,a pair of inserts extending through the base, said inserts being spacedapart from each other and being spaced inwardly from the end of the baseand cover, a threaded hole extending through each of said inserts, aterminal conductor on the upper side of the base and having its outerend positioned on top of the two inserts, a pair of holes through saidterminal conductor, each of said holes being in alignment with one ofthe holes in one of the inserts, a pair of threaded studs extending intosaid inserts, one or more conducting members each having two holestherethrough positioned on and extending between said pair of studs, anda groove in one or more of said conducting members between said studsfor clamping the end portion of a cable.

7. An electrical device having a base and cover of insulating material,a pair of inserts extending through the base, said inserts being spacedapart from each other and being spaced inwardly from the end of the baseand cover, a threaded hole extending through each of said inserts, aterminal conductor on the upper side of the base and having its outerend positioned on top of the two inserts, a pair of holes through saidterminal conductor, each of said holes being in alignment with one ofthe holes in one of the inserts, a plurality of plates having two spacedholes therethrough, each plate having a recessed area adjacent one holeand a raised area adjacent the other hole, said raised area on one platefitting into the recessed area in another plate when said plates areassembled, each plate having a transverse groove therein between saidholes, said grooves forming an opening between said plates for thecable, and bolts extending through said holes and the terminal conductorto clamp said plates against the conductor, and against the pair ofinserts.

8. An electrical device having a base of insulating material, openingmeans extending through the base, said opening means being spacedinwardly from the end of the base, a terminal conductor on the upperside of the base and having its outer end positioned on top of theopening means, a pair of holes through said terminal conductor, each ofsaid holes being over part of said opening means through the base, aplurality of plates having two spaced holes therethrough, each platehaving a transverse groove therein between said holes, said groovesforming an opening between said plates for a cable, bolts extendingthrough said holes and the terminal conductor to clamp said platesagainst the conductor and the cable, each hole having a flat sideadjacent to the groove in each plate, and each bolt having a flat sidecorrespondingto the flat side in a hole.

9. An electrical device having an elongated base of insulating material,opening means extending through the base, said opening means beingspaced inwardly from the end of the base, a terminal conductor on theupper side of the base, said conductor. having a fiat surface at itsouter end positioned over the opening means, a pair of holes throughsaid terminal conductor, said holes being spaced apart from each othertransversely of the base, each of said holes being over part of saidopening means through the base, at least two pairs of identicalconducting members, each of said members having two holes therethrough,each of said holes in the conducting members being in alignment with oneof the holes in the terminal conductor, each conducting member being ofsubstantially the same width as the terminal conductor, each conductingmember having a fiat surface on one side and a transverse groove in theside opposite the flat surface and between said holes, said groovesforming openings between said conducting members for cables when saidmembers are assembled in reversed relation with the fiat surface of onemember engaging the fiat surface of the terminal conductor and the fiatsurfaces of two of said members engaging each other, and bolts extendingthrough said holes and the terminal conductor to clamp the conductingmembers to the conductor.

References Cited in the file of this patent UNITED STATES PATENTS525,708 Herrick Sept. 11, 1894 1,976,533 Aflieck Oct. 9, 1934 2,025,563Bennett Dec. 24, 1935 2,337,155 Dibner Dec. 21, 1943 2,632,039 HammerlyMar. 17, 1953 FOREIGN PATENTS 453,639 Italy Dec. 9, 1949

